Agricultural soils contamination with cadmium (Cd) is a major driver of land degradation. It threatens soil biological integrity, crop productivity, and food security because of its high toxicity, persistence, and bio accumulative nature. The study aimed at assessing the potential of seed inoculation with Bacillus subtilis as a microbe-assisted strategy to mitigate Cd-induced soil degradation and plant stress in maize. The experiment consisted of six different treatments including control (CK), seed inoculation (SI), Cd at 25 mg kg-1 (Cd25), Cd25 with seed inoculation (Cd25SI), Cd at 50 mg kg-1 (Cd50), and Cd50 with seed inoculation (Cd50SI). Cd stress (Cd25 and Cd50) significantly degraded soil biological and chemical properties. Microbial diversity declined by over 60%, soil nutrient availability by up to 20%, and nutrient contents in plant tissues were reduced by 20%-60%. These changes resulted in approximately 50% yield loss while increased Cd accumulation up to 14-fold and elevated the health risk index (HRI >= 1). However, seed inoculation with Bacillus subtilis markedly alleviated these effects. Among all treatments, Cd25SI showed the most promising outcomes, with significant restoration of microbial community structure, increased abundance of beneficial phyla and genera, improved soil nutrient availability by 6%-23%, and reduced Cd bioavailability by 17% compared to Cd25. Cd25SI decreased Cd accumulation by 49%, 42%, and 48% in roots, shoots, and grains, respectively, while enhancing nutrient uptake across growth stages, including nitrogen (15%-65%), phosphorus (20%-70%), calcium (42%-68%), and iron (22%-33%). This treatment further reduced the health risk index by 48% and increased grain yield by 59% compared with Cd25. Overall, these findings demonstrate that Bacillus subtilis seed inoculation effectively mitigates Cd-induced land degradation by restoring soil microbial function, improving nutrient cycling, reducing Cd transfer to edible tissues, and enhancing crop productivity. This study provides integrated evidence supporting microbe-assisted remediation as a sustainable strategy for managing Cd-contaminated agricultural soils.

Flooding (FS) and drought (DS) reduce maize yield and water use efficiency by inducing anaerobic respiration and excessive reactive oxygen species (ROS). We tested foliar glycine betaine (GB) in three maize genotypes, GD668 (water-tolerant), ZF505 (water-sensitive), and GD0810 (drought-tolerant), subjected to FS or DS at the V3 stage using a factorial design of genotype × water stress × GB, with measurements at Day 4, Day 8, and after rewatering or drainage. Both stresses inhibited root growth, decreased leaf relative water content (RWC) and water potential (Wp), destabilized instantaneous water use efficiency (IWUE), and increased hydrogen peroxide (H2O2), superoxide (O2 -), and membrane permeability (Mp), with ZF505 most affected. GB improved root traits, increased RWC and Wp, stabilized IWUE, and reduced H2O2, O2 -, and Mp. GB also enhanced lactate dehydrogenase (LDH) activity, suppressed excessive pyruvate decarboxylase (PDC) activity, and limited ethanol (ETOH) and pyruvic acid (PA) accumulation. Transcriptomic and metabolomic analyses of GD668 and ZF505 indicated that GB up-regulated starch and sucrose metabolism and glycolysis genes (e.g., ZmSPS, ZmHK), modulated ZmPDC, and regulated lipid and betaine-related genes (ZmMGD, ZmDGD, ZmSQD2, ZmCHPT1, ZmBADH), supporting central carbon flux and membrane stability. A two-year field study (2022-2023) confirmed genotype-dependent mitigation, with the strongest effect in ZF505. Overall, the results indicate that GB stabilizes IWUE under opposite water stresses by moderating fermentative intensity and supporting membrane lipid remodeling, with stronger benefits in the sensitive genotype.

Maize kernel hardness, largely determined by the structural and compositional characteristics of the endosperm, is a key trait affecting grain quality, milling performance, and storage stability. Although vitreous and starchy endosperms exhibit markedly different physical properties, the underlying metabolic and transcriptional mechanisms—particularly the crosstalk between primary and specialized metabolic pathways—remain insufficiently understood. In this study, we conducted integrated metabolomic and transcriptomic analyses, along with cytological observations, to investigate these mechanisms using two contrasting maize inbred lines (D003, vitreous; D009, starchy) at three kernel developmental stages (18, 25, and 32 days after pollination, DAP). Cytological examination revealed that D003 endosperms comprise smaller, tightly packed cells containing polygonal starch granules, whereas D009 endosperms consist of larger, irregular cells with loosely arranged spherical starch granules. Metabolomic profiling revealed significantly higher levels of carotenoids—including carotenes (α-carotene, β-carotene) and xanthophylls (zeaxanthin, lutein)—in D003 kernels across all stages, implicating carotenoid biosynthesis in contributing to kernel hardness. Transcriptomic analysis identified starch and sucrose metabolism as the most significantly enriched pathway among differentially expressed genes (DEGs), with qRT-PCR validation confirming the downregulation of a key sucrose synthase gene (Zm00001eb313170). We propose a synergistic model in which transcriptional regulation of starch and sucrose metabolism—particularly reduced sucrose synthase activity—promotes the formation of a compact endosperm structure characterized by polygonal starch granules, while enhanced carotenoid accumulation reinforces cellular interfaces, collectively enhancing kernel hardness. These findings offer novel molecular targets for breeding strategies aimed at improving maize kernel quality.

Arsenic stress poses a significant threat to maize (Zea mays L.) production by disrupting plant growth and physiological functions. This study employed multivariate analysis to identify arsenic-tolerant maize varieties, evaluating growth parameters such as shoot fresh weight, dry weight, plant height, chlorophyll content, and arsenic accumulation across 20 maize varieties exposed to 50 mg kg-1. Significant variation in these indices enabled effective screening of arsenic tolerance. Cluster analysis based on D values classified GD562 and GD907 as highly tolerant, while GD911 and GD239 exhibited high sensitivity. GD562 exhibited enhanced tolerance by retaining calcium, zinc, iron, and sulphur in the roots, while redistributing nitrogen, phosphorus, potassium, and magnesium to the shoots, demonstrating superior nutrient management compared to the sensitive variety GD911. Additionally, GD562 showed elevated enzymatic antioxidant capacity (superoxide dismutase, peroxidase and glutathione reductase) at both the enzyme and gene expression levels, which alleviated oxidative damage by modulating reactive oxygen species. Additionally, enhanced soluble sugar accumulation contributed significantly to osmotic adjustment, thereby preserving cellular integrity under arsenic stress. Transmission electron microscopy analysis showed GD562 retained intact chloroplasts, thick cell walls, and stable vacuoles, highlighting its strong structural defense against arsenic toxicity, unlike the damaged cells of GD911. Collectively, these findings offer a holistic insight into the physiological, biochemical, ionomic and cellular mechanisms that underpin arsenic tolerance in maize, highlighting GD562's superior adaptive strategy under stress. This study emphasizes the importance of integrated analytical approaches for identifying arsenic resilient varieties, providing valuable insight for breeding programs and strategies to improving crop performance under heavy metal stress.

IntroductionTo increase the crop yield, the amount of agrochemicals used in field has increased in recent years. Moreover, indiscriminate use of chemical fertilizers has led to soil deterioration and compaction. Inclusion of straw and tillage practices to the field could play an important role in improving the soil quality and crop yield. Therefore, we hypothesized that combination of straw return and different tillage practices would result in improvement in soil health and crop productivity.MethodsTherefore an experiment was conducted a split plot design during 2018-2022. They were comprised of traditional planting with no straw return and straw return, accompanied by four different tillage methods: control (no tillage), rotary tillage (25 cm tillage depth), subsoiling (35 cm tillage depth), and subsoiling plus rotary tillage (35 + 25 cm tillage depth).ResultsResults showed that subsoiling along with rotary tillage enhanced soil total nitrogen (TN) by 9.0%, soil organic carbon (SOC) 7.5%, soil microbial biomass carbon (MBC) 6.8%, soil catalase (S-CAT) 9.6%, soil urease (S-UE) 4.1%, soil cellulase (S-CL) 14.5%, soil sucrase (S-SC) 10.8% and maize yield 3.0% compared to no tillage.DiscussionCorrelation analysis showed that (i) maize yield was significantly and positively correlated with S-SC, S-CL, S-UE, SOC, and TN. (ii) S-SC was significantly and positively correlated with TN, SOC, and MBC. (iii) TN was significantly and positively correlated with S-UE, and SOC was significantly and positively correlated with S-SC. It has been concluded that straw return coupled with subsoiling and rotary tillage is an appropriate approach to enrich soil nutrients, enzyme activities, and maize yield.

以桂单162为供试品种,采用大田试验,研究常规施肥(CK)、"一炮轰"和一次性缓控释肥(2 种)共4 个处理对春玉米农艺性状、干物质积累与分配、产量和经济效益的影响.结果表明:与常规施肥(CK)相比,一次性缓控释肥处理下玉米株高、穗位高、茎粗、叶面积和单株干物质积累量均较高;一次性缓控释肥处理下前期干物质在叶片和茎鞘中的分配比例均较低,后期在籽粒中的分配比例较高;一次性缓控释肥有助于增加玉米吐丝阶段穗的干物质积累量,提高成熟期玉米籽粒产量;一次性缓控释肥处理不仅能提高玉米百粒重,同时也能提高玉米穗行数和行粒数,穗长、穗粗和秃尖长均有不同程度的改善.T3 处理条件下,百粒重较CK提高 7.36％,秃尖长减少 28.8％,产量提高 3.96％,农民收益增长 25.20％.综之,与常规施肥相比,选用茂施牌一次性缓控释肥进行一次性底施,不仅可以为植株生长过程提供充足肥料,同时还可以合理调配干物质分布,增加籽粒中干物质分配比例,最终提高产量和收益.

Aiming at the problem of continuous acidification of soil in mountainous areas of Southwest China,long-term joint positioning tests were carried out at four test stations in Guiyang,Nanning,Mianyang and Enshi to compare the comprehensive effects of different acid regulation measures on soil improvement and maize yield increase,and further revealed the interaction between measures and maize yield,so as to provide support for the establishment of high and stable yield technical system of maize in mountainous areas of southwest China.The experiment set up five treatments:farmers’ habits（A1,CK）,soil conditioner application（A2）,lime application（A3）,organic fertilizer application（A4） and planting green manure before maize planting（A5）.The results showed that:（1）The four acid regulation measures significantly improved the soil acidification,among which A2 and A3 treatments had the best effect,with the pH increased by 0.9 units compared with the control,and for A4 and A5 treatments the pH increased by 0.7 and 0.5,respectively;The soil pH of A1 treatment in 2019 and 2020 decreased by 6.7% and 7.6%,respectively compared with that of the foundation soil sample（2016）.But under A2,A3,A4,A5 treatments,the soil pH in 2019 and 2020 increased by 8.0%,6.7%,2.5%,0.0% and 8.1%,7.1%,4.8%,0.3%,respectively,compared with that of the foundation soil sample（2016）;However,compared with A1treatment,the contents of soil organic matter,alkali hydrolyzable nitrogen,available phosphorus and available potassium in A4 treatment increased by 7.4 g/kg,30.2 mg/kg,11.6 mg/kg and 53.9 mg/kg,respectively,which was significantly higher than those in other treatments.（2）From the average yield in 2016～2020,the A4 treatment had the best yield increasing effect among the four measures,with the yield increasing rate of 11.7%.（3）The A4 treatment increased plant height,ear length,ear diameter,grain number per ear and 1000 grain weight most significantly.（4） The four acid regulation measures increased the dry matter accumulation in each growth stage,and the proportion of dry matter accumulation in six-leaf stage and silking stage were higher than that of the control,among which the accumulation of the A4 treatment was the largest.（5） The LAI and chlorophyll contents of A4 and A5 treatments at each growth stage were higher than those of the control. The increase proportion of grain to leaf ratio of A3 and A4 treatments were higher than that of A2 and A5 treatments. In conclusion,the four acid regulation measures could inhibit the trend of soil acidification,while the application of lime,conditioner and organic fertilizer could also improve soil pH,of which the first two measures had the most significant effect.Compared with other measures,the application of organic fertilizer could not only improve the soil pH and fertilize the soil,but also improve the agronomic properties of maize,optimize the structure of sink and source,promote the accumulation of dry matter,and then increase and stabilize yield.Therefore,from the perspective of acid regulation,soil fertility,increasing and stabilizing yield,the application of organic fertilizer is the most ideal acid regulation measure for acidified farmland in southwest mountainous maize planting area.

通过测定不同老化程度玉米种子的发芽指标、幼苗形态指标和生理生化指标,研究玉米种子的生理生化、生命活力因人工老化而发生的变化,为玉米种子老化机制及种子活力修复研究奠定基础.以桂 081 和桂单 1622 个玉米品种为试验材料,采用高温高湿(48℃、相对湿度95%)的人工老化方法,研究人工老化对玉米种子发芽指标、幼苗形态指标、相对电导率、丙二醛含量和过氧化物酶活性等指标的影响.结果证实了逐步增加老化时长,除 2 个品种种子的丙二醛(MDA)含量、相对电导率同步上升之外,其余生理指标如过氧化物酶活性、发芽指数、发芽率、发芽势、活力指数等均同步下降,老化 10d时,桂单0810 和桂单 162 种子的发芽势、发芽率、发芽指数和活力指数分别比对照降低60.32%和62.54%、55.44%和62.68%、49.52%和54.33%、65.63%和70.00%,而MDA含量大幅升高 90.91%和93.20%,过氧化物酶活性分别降低 60.16%和 83.04%.相关性分析表明,MDA含量、过氧化物酶活性与种子活力的相关性达到极显著水平.人工老化方式对玉米种子进行处理能够显著抑制其活力,影响幼苗的生长.相对电导率、MDA 含量和 POD 活性可用于衡量玉米种子的活力水平,而且种子耐老化能力存在品种间差异,桂单 0810 耐老化能力高于桂单 162.

Sustainable reduction of fertilization with technology acquisition for improving soil quality and realizing green food production is a major strategic demand for global agricultural production. Introducing legume (LCCs) and/or non-legume cover crops (NLCCs) during the fallow period before planting main crops such as wheat and corn increases surface coverage, retains soil moisture content, and absorbs excess mineral nutrients, thus reducing pollution. In addition, the cover crops (CCs) supplement the soil nutrients upon decomposition and have a green manure effect. Compared to the traditional bare land, the introduction of CCs systems has multiple ecological benefits, such as improving soil structure, promoting nutrient cycling, improving soil fertility and microbial activity, controlling soil erosion, and inhibiting weed growth, pests, and diseases. The residual decomposition process of cultivated crops after being pressed into the soil will directly change the soil carbon (C) and nitrogen (N) cycle and greenhouse gas emissions (GHGs), and thus affect the soil microbial activities. This key ecological process determines the realization of various ecological and environmental benefits of the cultivated system. Understanding the mechanism of these ecological environmental benefits provides a scientific basis for the restoration and promotion of cultivated crops in dry farming areas of the world. These findings provide an important contribution for understanding the mutual interrelationships and the research in this area, as well as increasing the use of CCs in the soil for better soil fertility, GHGs mitigation, and improving soil microbial community structure. This literature review studies the effects of crop biomass and quality on soil GHGs emissions, microbial biomass, and community structure of the crop cultivation system, aiming to clarify crop cultivation in theory.

随着人们对健康食品的需求增加,全国鲜食玉米消费市场不断壮大.广西与东南亚各国接壤,有较多的经济贸易联系,在"一带一路"发展中有较多的机遇.广西在鲜食玉米育种及产业上发展很快,优势显著,从种质资源丰富及特色明显、自主创新能力提升、育种实力增强及审定品种数量增多、种植面积逐年攀升、产业发展的优势、产业链初具规模和示范效应等方面详细论述了广西鲜食玉米的产业优势.从"一带一路"沿线国家农业发展角度、经济发展角度、推广阻力的角度分析了广西鲜食玉米产业在"一带一路"发展中的机遇,为广西鲜食玉米育种及产业发展提供支撑.

发展青贮玉米对畜牧业发展具有积极的作用.通过实地调研和查阅有关资料发现,广西青贮玉米生产具有政策层面、生态环境、市场需求、优质饲料缺口大、效率高、品质好等方面的优势,但广西青贮玉米生产也存在缺乏优质专用型青贮玉米品种、技术落后、生产及收获加工机械化程度低和效率低等问题.广西要立足资源优势,用好用足各类支持和鼓励政策,制定适宜本地青贮玉米发展的具体措施,积极开展青贮玉米优质专用型新品种的选育和审定等科研联合攻关,推广应用青贮玉米新品种,强化青贮玉米种植生产的技术培训和展示观摩,提高青贮玉米生产的规模化和机械化水平,大力发展青贮玉米,促进畜牧业健康发展.

Nitrate nitrogen (NO3-_N) leaching increased with nitrogen (N) fertilization under high water supply to the field negatively affected the maize growth and performance. This study aimed to understand the mechanisms of NO3-_N leaching on a biochemical basis and its relationship with plant performance with 5 different doses (0, 200, 250, 300, 350 kg N ha(- 1)) of N fertilizers under low (60%; LW) and high (80%; HW) water holding capacity. Soil and plant enzymes were observed at different growth stages (V9, R1, R3, and R6) of the maize, whereas the leachates were collected at 10-days intervals from the sowing date. The LW had 10.15% lower NO3-_N leachate than HW, with correspondence increases in grain yield (25.57%), shoot (17.57%) and root (28.67%) dry matter. Irrespective of the irrigation water, RubisCo, glutamine synthase (GS), nitrate reductase (NR), nitrite reductase (NiR), and glutamate synthase (GOGAT) activities increased with increasing N fertilizer up to the V9 growth stage and decreased with approaching the maturity stage (R6) in maize. In HW irrigation, soil total N, GOGAT, soil nitrate (NO3-_N), leached nitrate (LNO3-_N), root N (RN), leaf N (LN) were positively correlated with N factors suggesting the higher losses of N through leaching (11.3%) compared to LW irrigation. However, the malondialdehyde (MDA), hydrogen peroxide (H2O2), superoxide (O-2(-)), and proline were negatively correlated with the other enzymatic activities both under LW and HW irrigation. Thus, minimizing the NO3-_N leaching is possibly correlated with the LW and N300 combination without compromising the yield benefit and improving enzyme activities.

[目的]依据生理生化指标评价广西玉米品种萌芽期抗旱性,为广西抗旱玉米品种筛选和培育提供参考.[方法]利用20％PEG-6000溶液模拟干旱胁迫,对14个广西玉米品种进行萌芽期抗旱性试验,测定对照(蒸馏水)和干旱胁迫下各玉米品种胚芽的叶绿素、可溶性糖和丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,探究干旱胁迫对玉米萌芽特性的影响,并采用隶属函数法综合评价各参试玉米品种萌芽期的抗旱性.[结果]与对照相比,干旱胁迫下各参试玉米品种的生长发育均受到明显抑制,表现出种子萌发困难,胚芽生长缓慢,但不同品种受到的影响存在差别.方差分析结果表明,各生理生化指标在品种间和处理间的差异均达极显著水平(P<0.01).与对照相比,干旱胁迫下各玉米品种的叶绿素和可溶性糖含量减少,SOD、POD和CAT活性降低,MDA含量增加.隶属函数法评价中指标权重系数最大为MDA含量,达46.96％,其次为SOD活性,为21.77％.各品种隶属函数法D值在0.176～0.795,其中兆玉215和桂单162的D值大于0.7,属于强抗旱品种;桂单6205、桂单666和兆玉200的D值在0.5～0.7,属于抗旱品种;桂单660、桂单658、桂单673、桂单6209、桂单203和桂单6203的D值在0.4～0.5,属于中抗旱品种;桂单669、桂单671和桂单668的D值小于0.4,属于弱抗旱品种.[结论]叶绿素、可溶性糖和MDA含量及SOD、POD和CAT活性均可作为玉米萌芽期抗旱性评价指标,其中以MDA含量和SOD活性为主要评价指标.14个玉米品种中,兆玉215、桂单162、桂单6205、桂单666和兆玉200的抗旱性相对较强.

[目的]分析国际玉米小麦改良中心(CIMMYT)玉米自交系和广西玉米自交系主要农艺性状的配合力[一般配合力(GCA)和特殊配合力(SCA)]和遗传效应,为广西合理利用热带玉米种质提供参考依据.[方法]以4个广西骨干玉米自交系SP221、先21A、桂39722和桂兆18421为测验种,采用NCII遗传交配设计,对24个热带玉米自交系(12个CIMMYT引进系和12个广西自选系)的10个农艺性状(株高、穗长、穗粗、穗行数、穗位高、行粒数、秃尖、百粒重、出籽率和单株产量)进行配合力测定和遗传效应分析,评价各自交系的利用潜力.[结果]在24个热带玉米自交系中,DTMA-191和QP103各农艺性状的GCA表现优良,杂交组合中SP221×D13032、先21A×CMI460和先21A×D11231株高、穗长、穗粗、穗位高、行粒数、秃尖、百粒重、出籽率和单株产量的SCA表现优良.与12个CIMMYT玉米自交系各农艺性状的平均GCA相比,12个广西玉米自交系的秃尖表现较差,穗位高和百粒重表现较好.在所配制组合各农艺性状的SCA中,广西玉米自交系对提高单株产量和抑制秃尖具有明显优势,CIMMYT玉米自交系在降低穗位高和提高百粒重方面表现较好.遗传力分析结果表明,28个玉米自交系穗位高和秃尖的狭义遗传力分别为54.01％和52.46％,其他农艺性状的狭义遗传力均小于50.00％.[结论]玉米自交系DTMA-191和QP103各主要农艺性状综合表现优良,可作为重点利用 自交系;杂交组合SP221×D13032、先21A×CMI460和先21A×D11231的多数性状综合表现较好,可用于开展玉米品种区域试验.在育种实践中,提高单株产量和改良秃尖应侧重利用广西玉米自交系,降低穗位高和提高百粒重应侧重利用CIM-MYT玉米自交系.在热带玉米育种过程中穗位高和秃尖应进行早代选择,株高、穗长、穗粗、行数、行粒数、百粒重、出籽率和单株产量应进行晚代选择.

[目的]分析不同生态类型玉米品种的高产潜力及生长特性,为热区玉米品种合理布局和提高玉米生产能力提供参考依据.[方法]以我国北方和广西生态区域玉米品种(分别为XY335、DH11和DK008、GD688)为材料,在广西南宁市参考北方高产玉米增密栽培措施,从各品种玉米叶面积指数(ILA)变化规律、干物质积累特性、产量形成和计算机模拟技术(Hybrid-Maize模型)产量潜力等角度分析两个生态类型玉米品种的产量潜力.[结果]利用多项式模拟两个生态类型玉米品种ILA曲线的拟合效果较好,其ILA,max和ILA衰减速度不一致,其中灌浆期的ILA表现为广西生态类型品种(GD688和DK008)优于北方生态类型品种(XY335和DH11);密度和品种互作(D×V)对干物质积累无显著影响(P＞0.05,下同),品种间干物质积累量主要在开花—成熟期阶段表现差异显著(P＜0.05,下同);GD688和DK008的干物质生产能力明显优于XY335和DH11;增加种植密度对参试品种的穗长、穗粗和穗粒数负面影响显著,对提高产量效果不显著,其中产量与开花期—成熟期干物质积累量和成熟期植株干物质重呈极显著正相关(P＜0.01);广西生态类型玉米品种的产量潜力较北方生态类型高20.60％～24.20％;增加种植密度后,两个生态类型玉米品种的产量潜力增幅为14.30％～22.65％,产量潜力实现效率下降6.20％～15.90％,但北方生态类型玉米品种的产量潜力实现效率较高.[结论]在玉米生产上合理布局品种应充分考虑品种的生长特性和生态适应性.增加种植密度是提高玉米生产潜力的重要举措,广西生态区域玉米新品种的产量水平、耐密特性仍需进一步改良和提高.

Abstract Small farms are the mainstay of maize production in China. Its productivity is relatively low despite large farm inputs and the associated environmental footprints. Here, we studied public–private partnership (PPP) model for sustainable intensification of maize production to achieve co‐benefits of food security and environmental sustainability. The PPP model enabled the development of an effective partnership by bringing complementary skills, knowledge, proprietary products and technologies, and resources of public research community and private enterprises to create a new, operational maize farming system in China. We conducted on‐farm research with farmer participation in four major maize‐growing regions spanning temperate to sub‐tropical zones in China for 2 years. The PPP model achieved 78.7% of maize yield potential compared with 61.8% realized in smallholder farm (SHF) (11.0 Mg ha−1 vs. 8.6 Mg ha−1). Overall, environmental externalities of PPP were up to 32.7% lower than that of SHF, depending on the region studied. PPP significantly reduced reactive nitrogen losses by 31.3%–35.5% compared with SHF in both years. There was no significant difference between PPP and SHF for greenhouse gas emission in 2018, but it was significantly lower in PPP (19%) compared to SHF in 2019. Similarly, PPP significantly reduced soil acidification potential (by 10.1%–42.2%) and eutrophication of waterbodies (21.5%) in comparison to SHF. Overall, the net ecosystem economic budget increased 277 USD ha−1 with PPP. The PPP model provides new insights into improving food security and ecosystem and economic budget. As a logical progression to our research, future work should focus on (a) the reasons for the persistence of inter‐regional yield gap in PPP model and (b) to gain a better understanding of socioeconomic drivers critical for successful PPP in different maize‐growing regions.

通过研究不同耕作方式对玉米生长发育、产量及品质的影响,找出广西玉米生产中的最佳耕作方式.本试验以桂单162为材料,研究常规旋耕25 cm(对照)、深松35 cm+免耕、深松35 cm+旋耕25 cm和免耕共4种耕作方式下的玉米叶面积指数、株高、干物质积累、产量及其构成因素和玉米籽粒品质的变化特征.结果表明,与对照(RT)相比,深松方式下玉米株高、叶面积指数、单株干物质积累量均较高.与RT相比,深松不仅能使玉米百粒重显著提高,同时也能提高玉米的行粒数和穗行数,穗长、穗粗和秃尖长均有不同程度的改善,产量增幅为11.17％～13.59％.与RT相比,深松处理玉米籽粒淀粉含量降低4.19％～4.33％,脂肪含量提高1.93％～4.14％,蛋白质含量提高9.46％～15.49％.综之,与传统耕作(RT)相比,深松处理在提高玉米产量和品质方面效果明显,其中以深松35 cm+免耕的效果较优,适合在广西山地玉米生产中推广应用.

划分超甜玉米自交系的杂种优势群,筛选配合力高的甜玉米自交系,构建新的杂种优势更强的甜玉米群体,为优良甜玉米的选育提供依据.本研究选用23个自育超甜玉米自交系,采用NC Ⅱ设计得到60(3×20)个组合,研究它们的产量配合力效应并结合56K SNP标记将供试材料进行杂种优势群的划分.结果表明23个自交系的平均杂合率为2.59％,纯合度较高;除GX06和GX10,GX14和GX15,GX16和GX17的遗传相似度较高外,其余自交系之间的遗传相似度均小于90％,可作为不同的材料在育种上应用;测验系GX21和被测系GX01、GX03、GX12、GX13、GX18的产量GCA正向效应值较高,在产量性状上是非常优良的自交系;进化树、主成分分析和产量SCA聚类图将23个超甜玉米自交系分为GX21群、GX22群和GX23群,其中GX22(HJZ33)群称为父本群,包含的自交系为GX02、GX11、GX19、GX20及测验系GX22自身共5个,GX21(GTL273)和GX23(YC26)群称为母本群,包含的自交系为GX01、GX03～GX10、GX12～GX18及测验系GX21和GX23共18个.SNP标记和产量SCA分群结果基本一致,使用SNP标记化划分杂种优势群可以明显缩短玉米育种周期.

对于玉米育种而言,新组合的科学评价至关重要.以西南区55个玉米新组合为研究材料,对其产量等15个农艺性状进行灰色关联度分析、主成分分析和聚类分析.结果表明:不同玉米新组合农艺性状与产量的关联度大小依次为单株粒重>穗粗>籽粒含水量>百粒重>空杆率>穗行数>出籽率>穗长>倒折率>行粒数>茎粗>株高>穗位高>秃尖长.以产量最高组合1703为理想品种,综合评价表现较优的组合有成单388、绵1308、川单1751和荣玉1756.通过主成分分析将14个性状降为9个主成分,可解释表型变异的91.11％.依据主成分综合评价模型,可将所有组合分为6类,其中,川单1751、青青711、恩1010、成单388、绵1308、青青733和1703表现最优.聚类分析结果则将所有材料分为5类,结果与主成分分析法得出的结论基本一致.结果表明,玉米新组合绵1308、成单388、川单1751和1703表现最优.

玉米是世界上最重要的粮食作物之一,其种子质量的好坏直接影响粮食的产量,与食品生产安全息息相关,种子作为生产源头牵动着整个玉米产业链的发展.种子的质量还影响农作物的生存能力,是农业生产资料重要的组成部分.种子作为各种技术的关键载体,优质高产的种子对于提高食品安全和经济产量有着重要意义.随着农作物种子检测技术的不断进步,玉米的产量和质量得到有效提高.尤其是将近红外光谱分析技术应用在玉米种子检测中,使玉米种子检测质量与效果得到明显提高,为农户育种、种植及营销节省了成本,提高了经济效益.首先介绍了近红外光谱检测技术的应用原理,之后分析了近红外光谱分析技术的优缺点,最后探讨了近红外光谱分析技术在玉米种子检测中的应用.